You should look at other POS systems, get an idea of what's out there. POSitouch was the #2 selling software before Radiant bought Aloha, Digital Dining, Maitre D' and NCC are probably the next 3 best selling out there. DD just got bought by Heartland so you'd be dealing with a company like Aloha at some point. The rest are privately owned. I sell/support POSitouch, there is nothing that Aloha or Micros can do that POSitouch can't do and it's more of an open system so many more interfaces and integrations are available. Can't say a lot for the others but all are solid companies and have good dealers, some bad I am sure.
Middle of the road there are probably another dozen or so that have been around.